
#include<iostream>
#include<vector>
using namespace std;
class Solution {
public:
    bool isMatch(string s, string p) {
        if(p.length() == 0){
            return s.length() == 0;
        }

        int p_len = p.length();
        int s_len = s.length();
        vector<vector<bool>> dp(s_len+1, vector<bool> (p_len+1));
        dp[0][0] = true;

        for(int i =2; i<=p_len; i+=2){
            dp[0][i] = dp[0][i-2] && p[i-1]=='*';
        }


        for (int i = 1; i <= s_len; i++)
        {
            for (int j = 1; i <= p_len; j++)
            {
               if(p[j-1] == '*'){
                   //匹配0次j-是否匹配
                   if(j>=2){
                       dp[i][j] = dp[i][j-2];
                   }
                   //匹配多次看i-1是否匹配
                   if(i>=1 && j>=2 &&(s[i-1]==p[j-2] || p[j-2]=='.')){
                       dp[i][j] = dp[i][j] || dp[i-1][j];
                   }
               }
               else if(s[i-1]==p[j-1] || p[j-1]=='.'){
                   dp[i][j] = dp[i-1][j-1];
               }
            }
        }
    return dp[s_len][p_len];
    }
};